Nanomaterials in Coating and Colorant Technologies
Published on: Mar 3, 2016
Transcripts - Nanomaterials in Coating and Colorant Technologies
NANOMATERIALS & FUNCTIONAL COLORANTS a Revolutionary Concept? 1HCA General Lecture by Jelliarko Palgunadi
Lycurgus Cup (400 M)
A material can act differently when it’s nanometer-sized!
Why?Normally, metals absorb very little in the visible light spectrum, and are thus highlyreflective. This is the case with bulk (non-nano) gold. However, at very small particlesizes (~2-150nm) have high electron densities at their surfaces called surfaceplasmons, which interact with light through surface plasmon resonance.Depending on the particle size, the surface plasmons effect varies. At smalldiameters, these electrons strongly absorb green light (wavelength of about 520nm)and as the diameters grow larger, the surface plasmons absorb higher energy light. Asthe the nanoparticles get larger, their characteristics approach those of the bulksubstance.
Definitions• Nano means one billionth (10-9 m).• Nanomaterial and Nanotechnology - Deals with moleculesbetween one and one hundred nanometers in diameter.Manipulating individual atoms and manufacturing from thebottom up.
Nanomaterials as Functional Colorants Some State-of-the-ArtsWhat most apealling factor for nanocolorants is notmerely with their aesthethic values but mostly withtheir functionalities.
Wool colored with gold and silver nanparticles as functional textiles Nanogold wool Nanosilver wool Backscattered electronmicroscope image of merino wool containing nanogold. Anti-microbial activity of nanosilver wool against Staphylococcus aureusNSTI-Nanotech 2010, ISBN 978-1-4398-3401-5 Vol.1.2010, 792-795
Stretchable, Porous, and Conductive Energy Textiles Regular black bra or more? Motivation: Creating lightweight, flexible, and wearable electronic devices. Method: Incorporating single-walled carbon nanotubes (SWCNTs) and capacitance- enhancer nanomaterials into common textiles to produce highly conductive textiles.Liangbing Hu; Mauro Pasta; Fabio La Mantia; LiFeng Cui; Sangmoo Jeong; Heather Dawn Deshazer; Jang Wook Choi; Seung Min Han;Yi Cui; Nano Lett. 2010, 10, 708-714.
Porous textile conductor fabrication (a) Schematic of SWNTs wrapping around cellulose fibers to form a 3D porous structure. Cotton Ink: Single-walled carbon nanotubes dispersed in water containing sodium dodecylbenzenesulfonate (surfactant)(b) Conductive textiles are fabricated by dipping textile into an aqueous SWNT ink followed by drying in oven at 120 °C for 10min. (c) A thin, 10 cm × 10 cm textile conductor based on a fabric sheet with 100% cotton and Rs of 4 Ω/sq. (d) SEM image ofcoated cotton reveals the macroporous structure of the cotton sheet coated with SWNTs on the cotton fiber surface. (e) SEMimage of fabric sheet coated with SWNTs on the fabric fiber surface. (f) High-magnification SEM image shows the conformalcoating of SWNT covering and bridging between the fabric fibers. (g) TEM image of SWNTs on cotton fibers.
Properties of textile conductors(a) Sheet resistance of fabric and cotton sheet after SWNT coating, (b) Excellent mechanical properties of conductive textile,which shows the same values on both faces for either fabric or cotton. that is, strong adhesion between SWNTs and textileThe sheet resistances decrease by a factor of approximately 3 after (passing the scotch tape test), foldable, and stretchable.HNO3 treatment. (c) The SWNT-coated textiles show unusual stretching properties. The film sheet resistance decreases as the SWNT/fabric is stretched up to 240% of its initial length, after which the resistance starts to increase. (d) SWNT/cotton is resistant to water washing, thermal treatment at 200 C for 6 h, 4 M HNO 3 acid, and 2 M KOH.
Such strong binding of SWNT-fibers may be due to the following reasons:(1) Large van der Waals forces and hydrogen bonding exist between SWNTs and thetextile fibers.(2) The flexibility of SWNTs allow them to be conformally adhered to the surface ofcotton fibers which maximize the surface contact area between SWNTs and textilefibers.
Organic SC with porous textile conductor. (a) SC structure with porous textile conductors as electrodes and current collectors. The porous structure facilitates the accessibility of electrolyte. (c) Areal capacitance increases with areal mass loading of SWNTs. Comparison with previous studies shows that our porous conductors allow the highest mass loading and highest areal capacitance. The current used is 200 μA/cm2.(g) The schematic drawing of the stretchable SCs with SWNT/fabric as electrodes and with stretchable fabric as the separator(top). A SC under 120% strain (bottom). (h) The specific capacity for a strechable SC before and after stretching to 120% strainfor 100 cycles. The current density is 1 mA/cm 2.
Loading pseudocapacitor or battery materials in porous conductor. (a) Schematic drawing of electrodeposition of MnO 2 onto the SWNT coated textile fibers. Due to the porous structure, the MnO 2 particles are coated on all the textile fibers including those in the interior of the textile. (b) A photo of MnO 2-coated SWNT/Cotton. (c) SEM of a top view of conductive textile after MnO 2 coating. (d) SEM of cotton fibers inside the textile after peeling the fiber layers apart, which shows that the MnO 2 nanoparticles coated the fibers in the interior of the textile, not just the surface layers. (e) High-magnification SEM image showing the flower structure of MnO 2 particles on SWNTs.(f) Charge−discharge of aqueous SC with SWNT/cotton electrodes and 2 M Li2SO4 as the electrolyte with current of 20 μA/cm2. The arealcapacitance increases by 24-fold after MnO2 deposition. (g) Specific capacitance of SWNT/cotton with and without MnO2 for differentdischarge current densities. (h) Cycling stability of a SC with SWNT−MnO2 nanoparticles and porous textile conductor.
Ambient air detoxification at nano TiO2-coated surface CO2, H2O, non-toxic UV Source (λ <410 nm) matter VOC, Bacteria, etc os it i o n mp Deco e) anatas r face ( at ed su TiO 2-co Nano Honda-Fujishima Effect (Photocatalytic effect from TiO2)http://nano.or.id/index.php?option=com_content&task=view&id=93&Itemid=29Iran. J. Environ. Health. Sci. Eng. 5(2008)305-310
Self cleaning at nano TiO2-coated surface Moreover, TiO2 nanoparticles are transparent, thus, giving chance to maximize UV protection effect but will not interfere the desired color.http://www.nanopin.cz/en/en_page01.html
Some other challenging applications Nano composite plastics Heat, corrosion, abrasion resistant coatings And many more………… Radar, IR, absorbing materialshttp://www.ptonline.com/articles/chasing-nanocompositeshttp://www.motorship.com/features101/ships-and-shipyards/coating-uses-carbon-nano-technology-for-durability-and-performancehttp://www.popsci.com.au/technology/military/carbon-nanotube-stealth-paint-could-make-any-object-ultra-black